22 April Monday Morning Session 11:00 AM – 3:00 PM

Skywave OTH radars operate in the high frequency (HF) band (3-30 MHz) and exploit signal reflection from the ionosphere to detect and track targets at ranges of 1000 to 3000 km. The long-standing interest in OTH radar technology stems from its ability to provide persistent and cost-effective early-warning surveillance over vast geographical areas (millions of square kilometres). Specifically, the chief advantages of OTH radar are to cover geographical areas where it is not possible or convenient to site conventional microwave radars and to provide early-warning and wide-area surveillance that may be used for cueing line-of-sight sensors. Owing to the relatively lower signal bandwidths and large computing infrastructure relative to conventional line-of-sight radars on mobile military platforms, OTH radar is often at the forefront of demonstrating the operational effectiveness of advanced radar processing techniques before it is possible to implement these techniques in radar systems operating at higher frequencies.

The tutorial is organized into three parts. The first introduces the fundamental principles of OTH radar design and operation in the challenging HF environment. This serves to motivate and explain the architecture and nominal capabilities of modern OTH radar systems. The second describes experimentally-validated models of the skywave propagation channel as well as adaptive processing techniques for clutter and interference mitigation. The third delves into emerging applications, including OTH passive radar, blind signal separation, and multipath-driven geolocation for target echoes and HF emitters of interest. A highlight of the tutorial is the prolific inclusion of experimental results illustrating the practical application of robust signal processing techniques to real-world systems. Participants will receive a complimentary text book “High Frequency OTH Radar” McGraw-Hill, NY, 2013.